Saunarium Grunwald is a municipal sauna zone that opened in summer 2026 beside the new Grunwald city pool, run by POSiR as a textile-free area. It has the 50-person Sztorm Finnish sauna, a bio sauna, a steam bath, a saltarium with a brine graduation wall and an infrared cabin, with scheduled aroma and whisk sessions led by sauna masters. Open daily 14:00–22:00; one hour costs 55 zł and a full day 115 zł.